Don't be frustrated. I don't want to open a can of worms, but you can always resort to bringing to the surface those embedded melodies produced by chorded layered arpeggios using software. You have the rhythm and harmony growing out of it too. Almost like doing it all at once. But it still takes practice and skill.

(nice I'll try that) By the way I think I found how to 'spice up' creativity a little bit : getting out of the 'DAW LOOP ' ("Load Daw, Load Sounds, Set locators, Hit Record"). Such approach can sometimes lead to recording stuff that is 'not the best'. What I find really inspiring is loading a VstHost program, with a chain already set up (synth+effects) and then start playing with no purpose at all... this can 'shake up' things a little bit. But the best was recording small fragments of music and keeping them in a folder. When you go listening back after some time, you can always find some gem in there that you didn't realize were cool in the moment !

(nice I'll try that) By the way I think I found how to 'spice up' creativity a little bit : getting out of the 'DAW LOOP ' ("Load Daw, Load Sounds, Set locators, Hit Record"). Such approach can sometimes lead to recording stuff that is 'not the best'. What I find really inspiring is loading a VstHost program, with a chain already set up (synth+effects) and then start playing with no purpose at all... this can 'shake up' things a little bit. But the best was recording small fragments of music and keeping them in a folder. When you go listening back after some time, you can always find some gem in there that you didn't realize were cool in the moment !

I do something like that, deliberate recording of improv practice. it's a natural process for not just developing ideas but also discovering how you can develop ideas.

ultimately composition is about striking a balance between repetition and novelty, sameness and newness. If I'm in a rut, the solution is really about going back to simple questions about how elements of the music (rhythm, melody, harmony, timbre, texture, register, dynamics, stereo positioning, whatever) can be transformed/developed, repeated or introduced. AngelCityOutlaw posted some good examples.

the cool thing is that improvisation is a process of constantly asking yourself those questions. e.g. I can repeat the same idea, but transpose it... play the same idea in a different register... play a new idea in the same register... play the same idea with a new rhythm... play the same idea over a different harmony... play a new idea with a similar shape/contour/rhythm... embellish specific notes of the melody with various neighbour/passing tones... repeat a phrase, but change the end of it... play short phrases, call and response, long phrases... and on and on.

the cool thing is that improvisation is a process of constantly asking yourself those questions. e.g. I can repeat the same idea, but transpose it... play the same idea in a different register... play a new idea in the same register... play the same idea with a new rhythm... play the same idea over a different harmony... play a new idea with a similar shape/contour/rhythm... ... and on and on.

I wish it was like that for me. Unfortunately, most of the time, my improvisation regimen is an endless "flow of consciousness'', which, as good as it sounds, in the end becomes 'going nowhere' / me losing concentration.

What you described, to me, I'd call it "enlighted improvisation" ! I wish I could be so conscious of my playing.

So rather than improvise, start by composing variations on existing works. Take a theme from anything, and play it over and over, slowly introducing variations.

You’ll play some that don’t work, but over time you will find some that do work. It’s good practice to truly learn to improvise without hitting too many harmonic clams (although sometimes that’s not a bad thing, when playing blues-based stuff for example)

With melody a good way is thinking you are saying something - theres a phrase, and It needs an answer. Some answers Will be more elegant, some more creative - but to develop a melody you can think you are "answering" the phrase you already have.
Go creating answers, later you can harmonize the "story", cutting ir adding some phrases at Will. With practice there are many musical cliches that will appear to you - like going to a dramatic climax and going back to the start Melody, making a deeper melancholic intersection, or a way softer and feeric intersection... You'll see you are telling a story with the melody, that can be symmetric and didatic or sudden and irreverent, but that you'll decide while harmonizing the phrases you are creating.

Sometimes you'll get an amazing phrase on that scale but it doesnt fit on the story. What you do? You can keep it to another piece of music - that in the future you can tie back with this one. The most important now is to make this story you are creating to make Sense - to tell something, from the start to the end.

Ps: at least to myself thinking on theory is something that cant be done while composing. I recommend to forget even in which scale you are composing (in other words: dont compose at any scale). Follow your fingers and your ears, forget theory: theory can help the moment of composition if it had been practiced so much that your fingers will use it without you having to think. Dont think on anything thats external to what your fingers are saying.

Ill give an example: imagine you are writting a scene with characters full dressed in a romantic way and living a special and full of emotion night: you are writting the dialogues, spontaneous, that they say. Now imagine that you have a lot of abstract psychological knowledge sketched from books, do you think it will be better to think on it while writting rather delving in the story and let the characters flow?
If you have the psychological theories deep imbued in your mind, their dialogues will somehow reflect It, wanting you or not, and you can always change the text later to include the theories you like most - but while the characters are talking, let them talk. If you can realize you are not writting It, but the characters themselves are creating the story, then, you are where you wanted to be, you are composing.

Here's a little tip from my own "arsenal" (I'm not a great or even decent composer, so you might feel free to ignore things), which seems to work quite well in a number of cases:

- Chose any target note that suits the harmonic context well (most likely chord tones never do harm, but very often things such as the ninth might work as well). Don't overthink it, really, use the first one that is fine.

- Place it at the beginning of a part around beat one of the first bar (might as well be anticipated, such as on beat "4 and" of the previous bar).

- Come up with a small sequence of notes that you use as a pickup for the target note. Start simple, use just one or two notes and easy rhythms. For a start, the two diatonic (inside the scale) notes below the target note seem to pretty much always work awfully well.

This should already get you started. For variations:

- Instead of picking up the notes by playing two diatonic notes below, use the two diatonic notes above.

- Mix both pickups.

- Mix the pickup notes. So instead of A, B, C you might want to go for B, A, C.

- Chose another target note but stick with the same pickup principle. In case C was your first note and A, B was your pickup, in case your next target note would be D, your pickup would be B, C.
IMO this is working pretty well as it adds "plausibility".

- Use more pickups notes.

- Vary the pickup rhythmically.

In case you've never done such things, I'm sure you'll be able to at least see a lot of possibilities. Whether you like them or not - I wouldn't happen to know.

There are 3 kinds of people:
Those who can do maths and those who can't.